MEMBARRIER_CMD_QUERY					0
MEMBARRIER_CMD_GLOBAL					1 << 0
MEMBARRIER_CMD_GLOBAL_EXPEDITED				1 << 1
MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED		1 << 2
MEMBARRIER_CMD_PRIVATE_EXPEDITED			1 << 3
MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED		1 << 4
MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE		1 << 5
MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE	1 << 6